Why?
The current tram system takes up a lot of surface space, that would be more well used for other things. Also metros are cool
How?
Simple build a couple of metro stations and connect them with tunnels. We can also move some water elevators to the metro stations which will make the surface (especially blair mountain str) look much nicer.
Who?
i can do most of the world
Layout
here is a layout of my suggestion for a metro system https://imgur.com/AQdYYWG
I would cut out Revolution Square and just connect Castro Square, Blair Mountain Street, Lenin/Trotsky Street, and People’s Council. Everything else you suggest is literally like a 30 second walk. Actually my suggestion may be impractically close as well.
For Blair Mountain Street Station, extend it towards Revolution Square to access the mausoleum and mines.
Maybe use Nocheztli’s proposed high speed design?